Connector, reducer/adapter, flare to flareless

ABSTRACT

A high pressure fluid pipe connector for joining a threaded pipe to a  smo-walled tube; the connector also acts as a flow reducer. Special features of the connector are minimum number of parts, smooth continuous fluid surface contours, and relatively short compact connector length.

BACKGROUND AND SUMMARY OF THE INVENTION

In some fluid systems it is necessary or desirable to provide transitionconnection from a large diameter threaded pipe to a small diametersmooth-walled tube. In systems with which applicant is familiar, thetransition is accomplished by a relatively large number of threadedcouplings, seals and intermediate tubes. The present invention relatesto a transition connector employing a minimum number of component parts.

THE DRAWINGS

FIG. 1 is a sectional view through a connector mechanism embodying thisinvention.

FIG. 2 is a fragmentary sectional view of the FIG. 1 connector mechanismin a partially manufactured state.

FIG. 1 illustrates a fluid pressure system comprising an externallythreaded fitting or pipe 10, connector body 12, and smooth-walled tube14. Fitting 10 defines a relatively large diameter fluid passage 16,whereas tube 14 defines a smaller diameter passage 18; the connectorbody 12 defines a tapering or frusto-conical passage 20 for effecting arelatively smooth non-turbulent transition from the large diameterpassage 16 to the small diameter passage 18. Members 10, 12 and 14 mayeach be metal (ferrous or non-ferrous) or plastic as required fordifferent environmental conditions in chemical or food processingindustries.

Connector body 12 may be a one piece screw machine part having anannular flange 22 at its upper end accutely angled outwardly relative tothe connector body axis 24 at approximately thirty seven degrees. Thisangularity is selected to be the same as the included angle of thefrusto-conical end surface 26 on the lower end of fitting 10. Theconnector body 12 is pressured tightly against conduit surface 26 bymeans of a sleeve 28 and nut 30. As shown, sleeve 28 includes a radiallythickened annular head 32 engaged with an external frusto-conicalsurface area 34 on flange 22. Nut 30 comprises a main body 35 havingwrench flats 36 and an inwardly-extending lip 38 underlying the head 32of the sleeve 28, whereby threading of the nut 30 onto the fitting 10causes the annular lip 38 to apply pressure on head 32, thereby enablingthe head to force flange 22 tightly against end surface 26 of thefitting; this establishes a sealed joint maintainable at relatively highfluid pressures. In an actual assembly using ferrous components thejoint was maintained in a sealed condition under pressures in excess of700 p.s.i.

The joint between connector body 12 and tube 14 is sealed or completedby means of a conventional soft metal ring 40 and annular cap 32. Asseen in FIG. 1, this joint is in the "loose" state prior to the finaltightening-down operation. The upper end of tube 14 fits snugly within acylindrical socket machined into the lower end of connector body 12. Aflared entrance mouth 44 for this socket accommodates a soft metal ring40 above the end wall 46 of cap 42. Wrench flats 48 on the cap side wallpermit the cap to be threaded onto the end area of connector body 12thereby deforming ring 40 and moving the ring material upwardly throughmouth 44 into a trapped pressurized condition between tube 14 and mouth44 surface; the wall of tube 14 may be slightly deformed or indentedduring this operation.

It will be seen from FIG. 1 that sleeve 28 is captively retained ortrapped between shoulder 29 formed by the protruding wrench flats 31 andthe accutely angled flange 22. Initial assembly of sleeve 28 isnecessarily accomplished prior to the step of forming flange 22. FIG. 2illustrates the conditions of connector body 12, sleeve 28, and nut 30prior to formation of flange 22. With the parts stacked together asshown in FIG. 2, a flared die or punch (not shown) is moved or strokeddownward axially against the machined chamfer surface 33 to deform theupper annular end area of the connector body outwardly to the finalconfiguration shown in FIG. 1; the chamfer reduces the amount ofmaterial stress and strain during the die-formation operation, and alsotherefore the tendency for undesired cracking of flange 22. The machinedangle of chamfer 33 is about thirty degrees. During the deformation stepthe shoulder 29 supports the sleeve 28 in a fixed position on theconnector body 12; the annular head area 32 of the sleeve has an uppersurface that is angled at thirty seven degrees relative to body axis 24to thereby limit the flange 22 deformation and thus determine theangularity of the flange internal surface. This action produces aprecision fit of flange 22 on the frusto-conical end surface 26 offitting 10. When connector body 12 is formed of thermoplastic materialthe die is preferably heated to relieve stresses that would otherwiseoccur during a cold-forming operation.

The illustrated assembly is believed to have several advantages. Forexample, the defined flow passage comprised of surfaces 16, 20 and 18 isrelatively smooth without abrupt cavities or projections that wouldproduce turbulence losses. Also, the entire intermediate section of theconnector body 12 is internally tapered, as at 20, so that a relativelygreat flow reduction is achieved with a relatively short connector body12; this could be important where the flow reducer must be accommodatedin a limited space.

Of some practical importance is the fact that sleeve 28 and nut 30 areloosely trapped on the connector body 12 in the pre-usage state. Thetechnician is therefore able to build up a complete pipe system withouthaving to rummage through a large number of separated components; theconnector body, sleeve and nut are in effect pre-assembled.

The drawings illustrate one practical embodiment of the invention but itwill be appreciated that minor changes and variations can be resorted towithout departing from the spirit of the invention as set forth in theappended claims.

I claim:
 1. In the combination comprising an externally threaded pipe(10) defining a large diameter fluid passage (16), said pipe having anexternal frusto-conical end surface (26); and a smooth-walled tube 14having a cylindrical end section defining an internal passage (18) ofappreciably smaller diameter than the aforementioned fluid passage(16);the improvement comprising means for connecting the tube to thepipe in fluid-tight fashion, said connecting means including a one-pieceannular connector body (12) having a first end section that defines alarge diameter passage constituting a smooth continuation of theaforementioned passage (16), a second end section defining a smalldiameter passage constituting a smooth continuation of theaforementioned smaller passage (18), and an intermediate sectiondefining a tapering passage merging smoothly with the large and smalldiameter passages; the first end section of the connector body includingan annular flange (22) angled acutely outwardly relative to theconnector body axis to define an internal frusto-conical surface (33)matable with the frusto-conical end surface (26) on the pipe, saidannular flange also defining an external frusto-conical surface (34);means pressuring the connector body flange (22) against the pipe endsurface, comprising a sleeve (28) encircling the connector body and asleeve-engaged nut (30) threaded onto the pipe to draw the sleeve andconnector body toward the pipe end surface; said second end section ofthe connector body having a cylindrical socket therein snugly fittingaround the cylindrical end section of the aforementioned tube (14), themouth of the cylindrical socket being flared to define an annular cavitysurrounding the tube; a sealing ring (40) seated within said cavity, andan annular cap (48) threaded onto the second end section of theconnector body to compressively pack the sealing ring into the annularcavity.
 2. The combination of claim 1: said connector body (12) havingan outwardly extending wall that defines wrench flats (31) and ashoulder (29); the aforementioned sleeve being positioned on theconnector body between said shoulder and the aforementioned flange (22).3. The combination of claim 2 wherein said sleeve includes a radiallythickened head (32) engaged with said external frusto-conical surface(34); said nut (30) including an inwardly-extending lip (38) underlyingsaid thickened head to apply axial pressure thereon when the nut isthreaded onto the pipe.